Formalin fixation on HER-2 and PD-L1 expression in gastric cancer: A pilot analysis using the same surgical specimens with different fixation times

Table 5 Details of long-fixation cases

	Case No.	Formalin	Min. expression (6 h - 1 wk fixation)	Max. expression (6 h - 1 wk fixation)	Fixation period (mo)	Results after long fixation
HER-2:
	12	10% F	Score 3+	Score 3+	19	Score 2+
	22	10% F	Score 1+	Score 2+	3	Score 0
	26	10% NBF	Score 2+	Score 2+	20	Score 0
	27	10% NBF	Score 1+	Score 3+	18	Score 0
	31	10% NBF	Score 3+	Score 3+	16	Score 3+
PD-L1:
	20	10% F	1%-9%	80%	28	0%
	30	10% NBF	100%	100%	16	90%
	32	10% NBF	70%	90%	14	70%

F: Formalin; NBF: Neutral buffered formalin; HER-2: Human epidermal growth factor receptor 2; PD-L1: Programmed death-ligand 1.